*{
    margin: 0;
    padding: 0;
}
li{
    list-style: none;
}
.box{
    width: 451px;
    height: 400px;
    border: 3px solid #e1251b;
    margin-top: 20px;
    margin-left: 50px;
}
.left{
    width: 50px;
    height: 400px;
    border-right: 1px solid #e1251b;
    float: left;
}
li{
    width: 50px;
    height: 80px;
    text-align: center;
    line-height: 80px;
}
.right{
    width: 600%;
    height: 400px;
    margin-top: 0;
    margin-left: 51px;
}
.right div{
    float: left;
    width: 400px;
    height: 400px;
    display: none;
}
img{
    width: 400px;
    height: 400px;
}
.change{
    background-color: yellowgreen;
}